Topic IndexLibrary Index
Click a letter to see a list of conditions beginning with that letter.
Click 'Topic Index' to return to the index for the current topic.
Click 'Library Index' to return to the listing of all topics.
What is hypothyroidism?
Hypothyroidism is the most common type of thyroid disorder. It means your thyroid gland is not active enough. This tiny gland is found in the front of your neck. Its job is to make thyroid hormone. If the gland is underactive, it may not make enough thyroid hormone.
Thyroid hormones control how your body uses energy. They affect almost every organ in your body. When your thyroid doesn’t make enough of these hormones, parts of your body slow down.
What causes hypothyroidism?
The most common cause of hypothyroidism is an autoimmune disorder. This means your immune system starts to attack itself. It makes antibodies against the thyroid gland. The normal thyroid cells are overrun by white blood cells and scar tissue. Another cause may be treatment for an overactive thyroid gland. That may include radioactive iodine therapy or surgery. Hypothyroidism may also develop shortly after pregnancy.
A condition called secondary hypothyroidism can also sometimes happen. It’s when your pituitary gland stops working. The pituitary gland then no longer tells the thyroid gland to make thyroid hormones.
Newborns are tested at birth for hypothyroidism. This condition is called congenital hypothyroidism. It must be treated right away. It can affect a baby’s brain and nervous system.
Who is at risk for hypothyroidism?
You may be more likely to have hypothyroidism if you:
Are a woman
Are older than age 60
Have had thyroid problems or thyroid surgery in the past
Have a family history of thyroid problems
Have certain conditions, such as type 1 diabetes or rheumatoid arthritis
Have Turner syndrome, a genetic condition that affects women
Are pregnant or have had a baby within the last 6 months
Have an iodine deficiency. Your body needs iodine to make thyroid hormone.
What are the symptoms of hypothyroidism?
Symptoms are different for each person. They are usually hard to notice and start slowly. They may be mistaken for symptoms of depression. Here are the most common symptoms and signs:
Dull facial expressions
Tiredness and lack of energy (fatigue)
Not being able to handle cold
Puffy and swollen face
Sparse, coarse, and dry hair
Coarse, dry, and thickened skin
Hand tingling or pain (carpal tunnel syndrome)
Sides of eyebrows thin or fall out
Increased or irregular menstrual flow in women
These symptoms may look like other health problems. Always see your healthcare provider for a diagnosis.
How is hypothyroidism diagnosed?
Your healthcare provider will ask about your past health. You will also need a physical exam. Blood tests can also help diagnose hypothyroidism. They can measure the amount of thyroid hormone and thyroid-stimulating hormones in your blood.
How is hypothyroidism treated?
Treatment will depend on your symptoms, age, and general health. It will also depend on how severe the condition is.
The goal of treatment is to return your level of thyroid hormone back to normal. You may need to take medicine that gives you a dose of thyroid hormones. This dose may need to be changed over time. You will likely need to take this medicine for the rest of your life. You will need follow-up blood tests to make sure you are taking the correct dose of thyroid hormone replacement.
What are possible complications of hypothyroidism?
If your hypothyroidism is not treated, these complications may happen:
Low body temperature
When should I call my healthcare provider?
Tell your healthcare provider if your symptoms get worse or you have new symptoms. If you are a woman of childbearing age and want to become pregnant, talk with your healthcare provider first.
Key points about hypothyroidism
Hypothyroidism means your thyroid gland is underactive. It isn’t making enough thyroid hormone. The most common cause is when your immune system starts to attack itself.
Symptoms include dull facial expressions, tiredness, and weight gain.
Blood tests can help diagnose this condition. They can measure the amount of thyroid hormone and thyroid-stimulating hormone in your blood.
The goal of treatment is to return your levels of thyroid hormone back to normal.
Untreated hypothyroidism may lead to anemia, low body temperature, and heart failure.
Treatment may include medicine that replaces lost thyroid hormones. You often will need to take thyroid hormones for the rest of your life.
Tips to help you get the most from a visit to your healthcare provider:
Know the reason for your visit and what you want to happen.
Before your visit, write down questions you want answered.
Bring someone with you to help you ask questions and remember what your provider tells you.
At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.
Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.
Ask if your condition can be treated in other ways.
Know why a test or procedure is recommended and what the results could mean.
Know what to expect if you do not take the medicine or have the test or procedure.
If you have a follow-up appointment, write down the date, time, and purpose for that visit.
Online Medical Reviewer:
Maryann Foley RN BSN
Online Medical Reviewer:
Raymond Kent Turley BSN MSN RN
Online Medical Reviewer:
Robert Hurd MD
Date Last Reviewed:
© 2000-2020 The StayWell Company, LLC. 800 Township Line Road, Yardley, PA 19067. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.